The M604 is the Flagship radio in Icom’s line. The loud audio, separate knobs, high grade receiver performance and a full key pad for easy, give the radio quick and reliable performance. The M604A has excellent receive specifications, which allow a weak signal a better chance of being heard when louder signals are around it.

"our top pick - based on performance and features" -  Frank Lanier, Practical Sailor.  Read magazine review >

Output power:
Hailer: 30W listen back hailer
Foghorn: Built-in
GPS:Optional external GPS/NAV interface

Waterproof rating:

Large LCD
displayThe large full dot-matrix display is designed for optimum readability in any lighting condition. With the extra large font, the channel number is maximized on the display and upper and lower case characters can be easily read. When connecting to an external GPS receiver, the GPS information indication function shows course and speed data as well as position, date and time on the display.

Position request & report
Over and above the DSC, your own and other ships´ position data can be exchanged with the position request or position report functions. The received position information can be transferred to external GPS or navigation equipment*. In addition, the polling (request/ reply) function checks whether a specific ship is within the communications range. 

*NMEA 0183 format is required.

Hailer capability
When connected to an external hailer horn, communication with other boats, deck or dock hands is easy. The built-in 30W amplifier increases your talk power making your message loud and clear. Four foghorn patterns are also available. The RX speaker function, receiver-repeater allows you to monitor the received radio audio from a hailer horn on the deck or tower. You can also make an announcement on-board from the microphone.

Additional features
Favorite channel function
Dual/tri-watch function for monitoring Ch.16 and/or call channel
7 levels adjustable backlit display and keypad
Weather & alert channels
AquaQuake® draining function
Built-in ITU Class D DSC. 

 The Ultimate Marine Fixed Mount Radio                                

VHF Mounted Marine Radio



Frequency range
Type of emission    16K0G3E, 16K0G2B
Usable channels    USA, INT, CAN, WX channels
Power supply requirement    13.8V DC ±15%
Current drain (at 13.8V DC)
Transmit 5.5A (25W output)
Receive  1.5A (Max. audio)   
Operating temperature range    –20°C to +60°C ;
–4°F to +140°F
Antenna impedance    50Ω (SO-239)
Dimensions (W×H×D)
(projections not included)    220×110×109.4 mm;
821⁄32×411⁄32×45⁄16 in.
Weight (approx.)    1.4kg ; 3.09 lb

NMEA formats
Output     DSC, DSE

Output power    25W or 1W (at 13.8V DC)
Modulation system    Variable reactance
Max. Freq. deviation    ±5.0kHz
Frequency error    ±0.3kHz
Spurious emissions    Less than –70dBc
Residual modulation    More than 40dB
Adjacent Ch. power    More than 70dB

Intermediate freq.
1st 30.15MHz 21.7MHz (Ch70)
2nd  450kHz 
Sensitivity    0.22μV typ. (at 12dB SINAD)
Squelch sensitivity    Less than 0.32μV (threshold)
Adjacent Ch. selectivity    More than 80dB
Spurious response    More than 80dB
Intermodulation    More than 80dB
Hum and noise    More than 40dB

Audio output power    5.0W typ. at 10% distion
with a 4Ω load

Applicable U.S. Military Specifications
The IC-M604A and HM-162B/SW have been tested to and passed the following MIL-STD requirements and strict environmental standards.

Standard    MIL 810 C    MIL 810 D    MIL 810 E    MIL 810 F
Method    Proc    Method    Proc    Method    Proc    Method    Proc
Low Pressure    500.1    I    500.2    I, II    500.3    I, II    500.4    I, II
High Temp.    501.1    I    501.2    I, II    501.3    I, II    501.4    I, II
Low Temp.    502.1    I    502.2    I, II    502.3    I, II    502.4-3    I, II
Temp. Shock    503.1    I    503.2    I    503.3    I    503.4    I
Solar Radiation    505.1    I    505.2    I    505.3    I    505.4    I
Rain    506.1    I, II    506.2    I, II    506.3    I, II    506.4    I, II
Humidity    507.1    I, II    507.2    II, III    507.3    II, III    507.4    –
Salt Fog    509.1    I    509.2    I    509.3    I    509.4    –
Dust Blowing    510.1    I    510.2    I    510.3    I    510.4    I
Vibration    514.2    VIII, X    514.3    I    514.4    I    514.5    I
Shock    516.2    I, II, V    516.3    I, IV    516.4    I, IV    516.5    I, IV

Measurements made in accordance with TIA/EIA 603. All stated specifications are subject to change without notice or obligation.

 Supplied Accessories
Hand microphone
DC power cable
Mounting bracket kit